Sofa



FIG. 1 is a top and front perspective view of a sofa showing my new design;

FIG. 2 is an end perspective view thereof, the end view opposite that shown in FIG. 2 being the mirror image thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is rear view thereof. 

The ornamental design for a sofa, as shown and described. 